The effects of injection of absolute ethanol into the renal artery were investigated in 13 rabbit kidneys previously implanted with VX2 carcinoma. Eight rabbits with implanted tumors served as controls. The effects were evaluated by angiography and histology. Three days after implantation, tumors were demonstrated by angiography as relatively hypovascular areas in the subcapsular cortex of the kidneys. Following angiography, absolute ethanol (0.3 ml/kg) was injected into the renal artery. Repeat angiography with barium sulphate was performed after an additional 3 days (10 ethanol treated animals, 2 controls), 10 days (2 treated, 1 control) or 14 days (1 treated, 0 control). In treated animals the tumors were markedly smaller in comparison with those of the control group. The occlusion procedure, however, did not completely eradicate tumor cells. The histologic study of the implanted tumor confirmed the findings previously reported that viable tumor cells still remained in the peripheral portions of infarcted areas. This study demonstrated the beneficial, though not curative, short-term effects of transcatheter renal artery treatment with absolute ethanol in malignant renal tumors.